1. Field of Invention
The present invention relates to an orthodontic securing element for orthodontic therapy, which is also called a bracket.
2. Related Technology
A large number of juvenile and adult patients are treated orthodontically for correcting existing dysgnathias. In order to achieve the goal of the treatment as rapidly as possible and to the full extent planned, and also in order to be less dependent on the cooperation of the patient and to realize somatic tooth movements, firmly seated orthodontic apparatuses are in use.
The disadvantages of firmly seated apparatuses of this kind, such as brackets and bands, are a substantially more difficult oral hygiene (removal of calcium in the region of the brackets) and also a significantly reduced wearing comfort which is caused by the brackets which have been used up to now. Food residues remain around the brackets with bacterial settlement (plaque lawn and subsequent formation of caries) as a result, with the acids thereby arising causing decalcinations of the hard tooth substances, which leads as a result to destruction of the hard tooth substance. In addition mouth odors, the presence of which is very disagreeable for the patients wearing the apparatus, arise through the bacterial settlement and through the decomposing food residues. In addition conventional brackets have proved disadvantageous in so far as they offer an insufficient wearing comfort, can cause injuries to the lips, tongue and cheeks and negatively influence the lingual technique.
The problem (object) on which the invention is based is to create an orthodontic securing element (bracket) which has a greater wearing comfort.
This object is satisfied through an orthodontic securing element having a base and at least one holder which is arranged on the base, with a cover which covers over the base and the holder being secured to the base.
In accordance with the invention a preferably hood-like cover is placed onto the entire bracket so that the previously used parts of the holder, which have edges, are covered. Through this the required parts of the holder, for example slots, bracket wings, hooks and the like are hidden beneath the cover so that lips, cheeks or the tongue are not injured or irritated by these elements. Through a smooth and arched execution of the cover the self cleaning mechanism of the teeth is in addition substantially less impaired.
A further advantage of the complete covering of the securing element in accordance with the invention lies in the lower susceptibility to bacterial contamination. Through the covering in accordance with the invention all angles, edges and niches of the securing element or of its holder respectively are covered over with respect to the oral cavity so that no food residues can become fixed there and a bacterial attack is significantly reduced.
Advantageous further developments of the invention are described in the description, in the drawings and in the subordinate claims.
In accordance with a first advantageous embodiment the contour of the edge of the covering corresponds to the outer contour of the base of the securing element. Thus in this embodiment the entire bracket is substantially completely covered over by the covering so that the wearing comfort is optimized.
The covering is preferably executed to be hood-like and has no disturbing corners or edges. In this a convex curvature with radii of curvature which are as large as possible is preferred, since a shape of this kind is felt to be the least disturbing. Through a continuously arched surface both the bacterial attack and the irritation of the oral cavity are minimized.
The covering is preferably closed with the exception of two openings for passing a bow through, with the openings preferably being matched to the cross-section of the bow. Thus in this embodiment as well it is ensured that no food residues can penetrate under the covering in the region of the openings through which the bow is passed.
In order to enable a simple placing on of the covering onto the bracket with a bow secured thereto, the covering can in an advantageous manner be formed to be slit in the region of the openings. Through this the covering, which is preferably manufactured of an elastic material, can be briefly opened in the region of the slits so that the covering can be placed onto the base, with it being possible for the bow after being placed on to emerge through the openings which are provided. After the placing on the covering closes as a result of its elastic properties so that the bracket is completely protected in the direction of the oral cavity.
In accordance with a further advantageous embodiment of the invention the base has at its outer periphery a circumferential ledge, onto which the covering can be placed on. In this way the transition between the outer surface of the covering and the tooth surface can be formed without edges, with a good sealing between the base and the covering being ensured at the same time.
The base preferably has rounded off corners or is executed substantially ovally or elliptically respectively. Through a shaping of this kind disturbing corners or edges are also avoided in the region of the base, which further increases the wearing comfort.
The covering can be foldably secured to the base or be placeable onto the base, for example through a clamping seating. It is also possible to secure the covering through adhesive bonding.
In order to facilitate a measurement of the bracket position with a camera and a computer system, one or more registering aid devices can furthermore be arranged within the covering, for example at the holder, which are used as reference points.
In accordance with a further advantageous embodiment of the invention one or more hooks are arranged at the securing element which are likewise protected by the covering. In order for example to move teeth in a specific direction, these hooks can be folded out in accordance with the invention so that they project beyond the outer contour of the base and are easy to reach there. The hooks likewise have a rounded off and thus non disturbing outer contour. After the desired moving of the teeth the hooks can be moved back again so that the covering can be placed on onto the base.
In certain uses it can be advantageous to provide an additional opening for the passage through of the hook. This opening can for example be formed by a punched part which is broken out only when required. A renewed closing, for example through pivotal connection with the help of a film hinge or the like is also possible. In this case the hook can be used without it being necessary for the covering to be taken off.
In order to enable a rigid connection between palate bows and for example two premolars each as anchoring teeth, a connection mechanism between the palate bow and the bracket is provided in accordance with a further embodiment. Furthermore, a slit, which is also called a slot, and which serves for receiving the bow, is provided within the bracket. This slot has a reversible, individually insertable holding mechanism for the bow, so that the most diverse of orthodontic anchoring tasks can be solved.
In accordance with a further aspect of the present invention at least the outer surface of the covering has self cleaning properties, which has not previously been used in dental medicine for brackets. Self cleaning materials are known in principle and have a self cleaning effect which exploits the so-called xe2x80x9clotus effectxe2x80x9d and which is achieved through a surface with a predetermined roughness. Through this preset roughness, polar and nonpolar liquids can run off the surface in droplets, without residues, with contamination particles being taken along in the process (cf. C. Neinhuis and W. Barthlott, 1997: Characterization and distribution of water-repellent, self cleaning plant surfaces. Annals of Botany 79).
The self cleaning properties can preferably be achieved through an anti adhesion coating, for example of a sol-gel material. Sol-gel materials of this kind can be manufactured by a wet chemical method in which, starting from a liquid colloid-disperse system a reaction is initiated which leads to the build-upof a three dimensional network. For example silicic acid esters or metal alkoxides, which react through hydrolysis and condensation to form an inorganic network, can be used as starting compounds. Through this, repellent surfaces can be produced which have the desired self cleaning properties.
Preferably, not only the outer surface of the covering, but also the entire securing element is provided with an anti adhesive coating, with it not being necessary to equip the lower side of the base, which is secured at a tooth, with a coating of this kind.
In accordance with a further aspect of the present invention, storage locations for bacteriostatic and/or bactericidal substances are provided at the securing element and inside the covering. Gels or pastes with bacteriostatic or bactericidal action can be introduced into these storage locations, for example cavities. Silver-fluorine compounds, phenol compounds and the like come under consideration as bactericidal substances.
The present invention relates not only to an orthodontic securing element, but also to the described covering, with which conventional brackets can be subsequently equipped.